JPH0569100B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION The present invention relates to novel cycloaliphatic triisocyanates and methods for their production. Aliphatic and cycloaliphatic diisocyanates such as 4,4'-diisocyanatodicyclohexylmethane, 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate and hexamethylene diisocyanate are photostable with excellent weatherability. used industrially in the production of coating materials [H. Wagner, H.F.
Wagner.HFSarx, Lackkunstharze, 5th
Edition, Carl Hanser Verlag, Munich), 1971
, pp. 153 ff.
H. Kittel, Lehrbuch, Berlin-Oberschwantorf
der Lacke und Besehichtungen, Verlag WA
Colomb in der Hennemann, GmbH, Berlin−
Oberschwandorf), 1973]. However, low molecular weight isocyanates have high vapor pressures and are toxic in some cases. They are therefore modified before use, for example by trimerization, biuretation or by prepolymerization by reaction with low molecular weight polyols, in order to meet industrial hygiene requirements during further processing. Such modification yields higher molecular weight and higher functionality compounds with virtually no vapor pressure [e.g.
Kunstschutzf-Handbutzuf by Bezker and Day Brown, Karl Hanser-Förlag, Munitzk/Vienna, 1983
, Volume 7, “Polyurethane” (GW Becker and
D.Braun, Carl Hanser Verlag, Munich/
Vienna (1983), Vol.7, “Polyurethane”), 541−
See page 543]. However, post-modification of monomeric diisocyanates is associated with several drawbacks. The additional step of modification often requires more effort and additional costs, especially since technically elaborate procedures are required to separate the modified product from excess monomer. Furthermore, monomeric diisocyanates can be formed by recleavage during storage of modified polyisocyanates. In addition, modified polyisocyanates generally have a relatively high viscosity, and are suitable for low-solvent or no-solvent applications.
Even if it is suitable, it is only suitable to a limited extent. Furthermore, they cannot be purified by distillation due to their low vapor pressure. SUMMARY OF THE INVENTION It is an object of the present invention to provide new cycloaliphatic triisocyanates. It is also an object of the present invention to provide cycloaliphatic triisocyanates useful in the production of photostable coating materials with excellent weather resistance. Another object of the present invention is to provide a relatively simple method for producing cycloaliphatic triisocyanates. These and other purposes that will be obvious to those skilled in the art are

This is achieved with triisocyanates and isomer mixtures of triisocyanates corresponding to the formula: ##STR1## in which R represents hydrogen or a C ₁ -C ₄ alkyl group. These isocyanates and their isomeric mixtures have the formula

It is produced by phosgenating a triamine corresponding to the formula (wherein R is as defined above) and an isomer mixture of the triamine. DETAILED DESCRIPTION OF THE INVENTION The invention is based on the formula

It relates to a triisocyanate corresponding to ##STR00003## in which R represents hydrogen or a _C1 - _C4 alkyl group, preferably hydrogen or a methyl group. These triisocyanates may be in positional and/or stereoisomeric forms. The invention also relates to a process for the preparation of these triisocyanates, in which the underlying triamine is phosgenated by methods known to those skilled in the art. The starting material for the phosgenation process of the present invention has the formula

It is a triamine corresponding to the triisocyanate, which corresponds to ##STR8## where R is as defined above. The starting material for the production of the polyamine corresponding to the formula () used in the process of the invention is the following formula:

The corresponding aromatic triamine is represented by: ##STR00003## where R is as defined above. These aromatic triamines can be prepared in known manner. For example, N-[4(2)-aminobenzyl]-aniline is combined with an optionally alkyl-substituted phenylenediamine according to Beilstein 13H, page 309 or according to German Patent Specification No. 107 718. Therefore, it can be reacted. Aromatic triamines can be prepared by combining (i) 3- or 4-nitrobenzyl halide, benzyl alcohol or nitrobenzyl chloride isomer mixtures with (ii) nitrobenzene, alkyl-substituted nitrobenzene, alkylbenzene or benzene in the presence of a Friedel-Crafts or acid catalyst. It can also be prepared by reacting the reaction product thus obtained by nitration to form the corresponding trinitro compound and hydrogenating the nitro group according to European Patent Application No. 46917. Due to the nature of their preparation, the trinitro compounds obtained by the last of the above processes and the aromatic triamines prepared therefrom are industrial mixtures which may contain, in addition to the corresponding trifunctional compounds, also difunctional compounds. be. However, the difunctional compounds present in these mixtures can be removed by distillation in the amine stage if desired. Representative examples of suitable starting materials of formula () are 2,4,4'(2')-triaminodiphenylmethane, 2,6,4'(2')-triaminodiphenylmethane, 4, 6,4'(2)-triamino-3-methyldiphenylmethane, 2,6,4'(2')-triamino-3
-methyldiphenylmethane, 3,5,4'(2')triamino-4-methyldiphenylmethane, 2,
6,4'(2')-triamino-4-methyldiphenylmethane, 3,5,4'(2')-triamino-2-methyldiphenylmethane, 4,6,4'(2')-triamino -2-methyldiphenylmethane and mixtures thereof. The corresponding ethyl-, isopropyl-, n-propyl- or n-, iso- or tert-butyl-substituted triaminodiphenylmethanes may also be used. However, preferred starting materials are methyl substitutions of the type that accumulate in the trinitration, reduction of the nitro group and optionally purification by calcined distillation of hydrocarbon mixtures consisting of 2- and/or 4-methyldiphenylmethane or these isomers. It is an isomer mixture of triaminodiphenylmethane or a technical mixture thereof with the corresponding diamine. Particularly preferred starting materials obtained by this method generally contain 80 wt% or more triaminodiphenylmethane, of which 90% or more by weight (wt%) consists of aminobenzyldiaminotoluene isomers. The starting materials may be exclusively aromatic triamines corresponding to formula () and/or mixtures of these triamines, or these triamines and the corresponding diamines, which preferably contain an amino group on each aromatic ring. It may be a mixture of
These mixtures are 90wt based on the whole mixture
%, preferably up to 50 wt%, more preferably up to 20 wt% of these diamines.
Polyamine mixtures having a high aromatic diamine content due to their method of preparation can be completely or almost completely freed of diamines by distillation prior to hydrogenation to produce the starting materials for the phosgenation process of the invention. . However, it is also possible to subject the aromatic polyamine as such to hydrogenation and then remove the diamine and other by-products formed during hydrogenation from the hydrogenated polyamine mixture. Furthermore, in order to obtain an almost pure polyisocyanate corresponding to formula (), the phosgenation process of the invention is completed before the difunctional end product (obtained by phosgenation of the corresponding diamine) and, if any, Other by-products can also be separated by distillation. Nuclear hydrogenation of aromatic polyamines corresponding to formula () is generally carried out by known methods [P.
Rylander, Catalytic Hydrogenation in Organic Synthesis,
Academic Press, New York, San Francisco, London (P. Rylander, Catalytic
Hydrogenation in Organic Syntheses,
Academic Press, New York, San.
Francisco, London), 1979, p. 190]. Aromatic amines are catalytically hydrogenated until all hydrogen is absorbed. Hydrogenation is 100 to 300℃ at 20 to 300℃.
At a pressure of 300 bar, preferably between 150 and 250°C
at a pressure of 70 to 300 bar, more preferably
It is carried out at a pressure of 120 to 300 bar. The hydrogenation is carried out in the presence of 0.1 to 30 wt% of hydrogenation catalyst, preferably 0.1 to 10 wt% (based on catalytically active metal and diamino compound).
Suitable catalysts are optionally activated carbon, silica gel,
Elements of subgroup 8 of the Periodic Table of the Elements and catalytically active inorganic compounds of these elements, which may be applied on an inert support such as calcium carbonate, barium sulfate and especially aluminum oxide. Particularly suitable catalysts include: ruthenium, alone or in chemically bonded form, platinum,
Rhodium, nickel and/or cobalt catalysts. Particular preference is given to ruthenium or catalytically active ruthenium compounds. Examples of suitable ruthenium compounds are ruthenium oxide; barium parthenite; sodium, potassium, silver, calcium and magnesium ruthenate; sodium perruthenate; ruthenium pentafluoride; ruthenium tetrafluoride hydrate and ruthenium trichloride. If a support for the catalyst is used, the metal content of the supported catalyst is generally 1 to 10 wt%, preferably 1 to 10% by weight.
It is 5wt%. The amount and type of catalyst used are of course not critical in any way to the hydrogenation reaction. It is often advisable to carry out the hydrogenation reaction in the presence of ammonia. This is because undesired deamination reactions and the formation of secondary amines as by-products can be suppressed by the presence of ammonia. If ammonia is used, the amount used is generally based on the starting material to be hydrogenated.
0.1 to 30 wt%, preferably 5 to 10 wt%. Hydrogenation may be carried out in the absence of a solvent or in the presence of an inert solvent. Generally, low melting point or liquid aromatic amines are hydrogenated by themselves, while high melting point diamines are hydrogenated in solution. Suitable solvents are low-boiling compounds that are inert under the reaction conditions, preferably alcohols such as methanol, t-butanol, ethanol, n-propanol, i-propanol; dioxane, tetrahydrofuran, ethers such as diethyl ether, and cyclohexane. Hydrocarbons such as The hydrogenation reaction can be carried out continuously in a tube reactor or in a cascade of pressure vessels. Hydrogenation is carried out in batches in a stirred autoclave, filling the autoclave with catalyst, substance to be hydrogenated and solvent (if any), purging the autoclave repeatedly with inert gas and optionally introducing ammonia. It is preferable to carry out by. Hydrogen is then introduced under pressure, the mixture is heated to the reaction temperature and hydrogenated until the pressure remains constant,
Next, the mixture is further stirred at the same temperature for about 0.5 to 5 hours.
After cooling the reaction mixture and separating the catalyst, the hydrogenation product is generally purified by distillation. The hydrogenation products accumulate in high yields and by-products can be removed by distillation, if necessary, as described above. Even after being purified by distillation in this way, triamines are generally sterically and optionally positionally
It is a mixture of isomers. Purification by distillation as described above yields a triamine of which at least 80 wt%, preferably at least 90 wt%, corresponds to the general formula (). However, even hydrogenated products that have not been purified by distillation fall within the scope of formula () as triamines. although they are mixtures of positional and/or stereoisomers or
in admixture with up to 90 wt%, preferably up to 50 wt%, more preferably up to 40 wt% of other optionally alkyl-substituted di- and/or triamines having a diphenylmethane, benzylcyclohexane or dicyclohexylmethane structure. Although it may exist. The diamine may be present if the starting material used is an aromatic triamine containing an aromatic diamine and/or if the cycloaliphatic ring undergoes some deamination during the hydrohydration reaction. However, deamination can be suppressed by the presence of ammonia during the hydrogenation reaction. Even very small amounts of monoamines can be produced by deamination. However, they can be removed very easily by distillation. If the hydrogenation is incomplete, polyamines with diphenylmethane or benzylcyclohexane structures will be present in small amounts in the hydrogenation products, but generally do not adversely affect their usefulness. Generally, it is not necessary to purify the hydrogenated product by distillation before use in the phosgenation process of the present invention. This is because, as already mentioned, the final product can be purified by distillation after the phosgenation reaction. The suitability of the hydrogenated products for use in the phosgenation process of the invention is not influenced by their positional and stereoisomerism or by isomer distribution. Representative examples of starting polyamines suitable for the phosgenation process of the present invention are cycloaliphatic triamines corresponding to the aromatic triamines described above, optionally with the by-products formed during the hydrogenation reaction removed by distillation. be. The starting polyamines used in the phosgenation process of the invention correspond substantially to the aromatic polyamines or polyamine mixtures from which they are prepared. In a practical application of the process of the invention for preparing new triisocyanates, the phosgenation of the starting amines or their salts is carried out in the presence of an inert organic solvent by methods known to those skilled in the art. [Houben-Weyl, Methoden der Organischen Hemie, Georg Teime Verlag, Schüttgart (1952), vol. 8, 4th edition (Houben-Weyl,
Methoden der organischen Chemie, Georg
Thieme Verlag Stuttgars (1952), Vol.8, 4th
Edition), see pages 120 et seq.]. In this context, "starting amine" means a pure compound of the general formula (), optionally a mixture of positional and stereoisomers, and up to 90 wt%, preferably 50 wt% thereof.
%, more preferably up to 20 wt. %, of other optionally alkyl-substituted di- and/or triamines having a diphenylmethane, benzylcyclohexyl or didichlorohexylmethane structure. be done. The above percentages are based on the entire mixture. Suitable phosgenatable salts are preferably hydrochlorides or ammonium carbamates formed by saturating the polyamine solution with gaseous hydrogen chloride or carbon dioxide. In principle, it is also possible to phosgenate other salts, which are formed, for example, by neutralizing polyamines with protons. The selectivity of the phosgenation reaction depends to a large extent on the amine concentration and on the excess of phosgene. Preferably,
Phosgene is used in large molar excess, while the amine to be phosgenated is used in highly diluted form. Generally the molar excess of phosgene is 100 to 2000
%, preferably 100 to 1000%. The amine concentration is generally 0.1 to 15 wt%, preferably 5 to 10 wt%, based on the total amount of amine and solvent.
It is. The solvent used may be any inert organic liquid or mixture thereof having a boiling point in the range from 60 to 250°C, such as halogenated hydrocarbons and aromatics, preferably chlorides. Examples of suitable solvents are xylene, mesitylene, chlorobenzene, dichlorobenzene, trichlorobenzene, chloronaphthalene and dichloroethane. The reaction can be carried out in one step by thermal phosgenation at temperatures ranging from 100 to 250°C or by -20 to 250°C.
It can be carried out in two stages by cold/hot phosgenation at a temperature of 0.degree. C. and under normal pressure. When using free amines as starting compounds (basic phosgenation), ammonium carbamic acid chloride is first formed at temperatures ranging from -20 to +60°C and then further reacted with phosgene at 20 to 250°C to give the polyisocyanate. generate. The final product of the process is generally purified by evaporation of the solvent after dephosgenation and subsequent distillation under reduced pressure. The final product of the process of the invention (ie the new triisocyanate) was obtained in high yield in the form of a colorless to yellow, low viscosity liquid. These triisocyanates are valuable synthetic components in the production of polyurethane plastics by the isocyanate polyaddition process. The positional and/or stereoisomerism of the new triisocyanates largely corresponds to the isomerism of the triamine used in the phosgenation reaction. In general, there is no need to separate the mixtures that accumulate in the phosgenation process into individual positional and/or stereoisomers, since the final product can be used directly. Diisocyanates and other by-products (in particular phosgenation products of triamines with a diphenylmethane or dicyclohexylmethane structure), which may optionally be present in admixture with triisocyanates corresponding to the formula (), can be completely or partially removed from the triamines by distillation. Can be separated. However, many uses of the triisocyanates of the present invention do not require such purification. This is because even corresponding polyisocyanate mixtures containing more than 50% by weight, preferably more than 80% by weight of polyisocyanates of the formula () represent valuable new starting materials for polyurethane chemistry. The triisocyanates of the invention, or mixtures thereof with the abovementioned by-products, containing at least 50 wt.%, preferably at least 80 wt.%, of triisocyanates of formula () can be used with particular advantage for the production of polyurethane lacquers and coating materials. . The triisocyanates of the invention are known to those skilled in the art. It can be used in place of or in conjunction with the polyisocyanates conventionally used in the production of the plastics. One particular advantage of the polyisocyanates of the present invention over the state of the art Lacquer class polyisocyanates is that they are low viscosity distillable liquids. Nevertheless, the new triisocyanates have sufficiently low vapor pressures to meet the industrial hygiene requirements for the production of polyurethanes, in particular polyurethane lacquers. The invention is further illustrated by the following examples. All percentages in the examples are weight percentages unless otherwise specified. Analysis of the isomer distribution of intermediates and final products was performed by gas chromatography. Example 1 (1a) 2,4-diaminotoluene was converted into N-[4-
[aminobenzyl] - industrially produced N-aminobenzylaniline containing 80% or more aniline and in the presence of hydrochloric acid (degree of protonation: 50%)
by reacting with , then neutralizing the catalyst with sodium hydroxide and purifying it by distillation.
4,4'-diaminodiphenylmethane 1.4%, 4,
6,2'-triamino-3-methyldiphenylmethane 10.2%, 2,6,4'-triamino-3-methyldiphenylmethane 6.8%, 4,6,4'-triamino-3-methyldiphenylmethane 78.7 %
A technical amine mixture was obtained consisting of 2.9% of polyamines and other aromatic polyamines. A 700 ml stirred autoclave was initially charged with 380 g of this amine mixture, 380 g of tertiary butanol and 76 g of ruthenium-aluminum oxide supported catalyst (5% Ru) and hydrogenated under a pressure of 100 bar (after repeated purging with nitrogen and hydrogen). introduced. The contents of the autoclave were initially heated to 130℃ (melting point of the amine mixture).
, start the stirrer, and increase the temperature to 200
Raised to ℃. Hydrogen was then introduced at constant temperature and under a pressure of 275 bar until after 5.25 hours the pressure in the autoclave remained constant. The contents of the autoclave were then cooled to about 60°C, after which time the autoclave was vented and the crude product was taken up in methanol. The catalyst was filtered off with suction and the product was distilled.
364.4 g of an amine mixture having the following composition determined by gas chromatography was heated at 115-170°C/
Distilled at a boiling temperature of 0.9 mbar: 30.3% diaminomethyldicyclohexylmethane (mixture of isomers), 61.3% triaminomethyldicyclohexylmethane (mixture of isomers) and 8.4% unidentified amine. The triamines obtained contained almost exclusively one amino group on the cyclohexane ring without alkyl substituents and two amino groups on the methyl-substituted cyclohexane ring. Another distillation cycle is 139-170℃/0.1
This yields 164.0 g of hydrogenated product boiling at mbar and gas chromatographic analysis shows that
92.1% was triaminomethyldicyclohexylmethane isomer. (1b) 95 g of the hydrogenated product purified by distillation according to (1a) were dissolved in 700 ml of dry chlorobenzene and carbon dioxide was introduced into the resulting solution at 40-45° C. up to the saturation point. The resulting suspension was dissolved in a solution of 250 g of phosgene in 700 ml of chlorobenzene.
It was added dropwise with vigorous stirring at °C. The reaction mixture is
Heat to boiling temperature while introducing phosgene and boil for 2 hours until the solids are completely dissolved. The reaction mixture was then phosgenated for a further 3 hours, during which time phosgene was introduced at a rate of approximately 300 g/h. Excess phosgene was dissipated by injecting nitrogen into the solution at boiling temperature for 1 hour.
The solvent is distilled off under a pressure of 1000 to 100 mbar and the crude isocyanate is removed after flash distillation at 180-230°C/0.3-0.5 mbar.
107g was obtained. After redistillation, NCO content 38.6%
105 g of triisocyanatomethyldicyclohexylmethane of the formula () (R=CH ₃ ) in the form of an isomer mixture of are obtained in the form of a distillate at 165-170° C./0.05 mbar. Example 2 (2a) Ruthenium-aluminum oxide supported catalyst (5%
Ru) 14g and N-(4(2)-
350 g of the condensation product of (aminobenzyl)-aniline and m-phenyldiamine were charged: 2.2% m-phenylenediamine, 0.6% 2,6,4'-triaminodiphenylmethane, 14.5% 2, 4,2'-triaminodiphenylmethane and 82.7% 2,4,4'-triaminodiphenylmethane. After repeated purging with nitrogen and hydrogen,
39g of liquid ammonia was added. Hydrogen was introduced under a pressure of 100 bar and the autoclave
Heated to 140°C. Hydrogenation was then carried out with stirring at 275 bar of hydrogen. Temperature 200 in 23 hours
℃ and continued hydrogenation at the same temperature for an additional 7 hours. Then cool the autoclave to 60℃,
Gas was degassed and the catalyst was separated by suction filtration at 70°C. Distillation at 127-185°C/0.4 mbar produces a mixture of cycloaliphatic amines with the following composition:
gave 337.5 g: 2.5% monoaminodicyclohexylmethane (mixture of isomers), 21.4% diaminodicyclohexylmethane (mixture of isomers), 74.6% triaminodicyclohexylmethane (mixture of isomers), 0.6% of 4(2 ,4-diaminobenzyl)-cyclohexylamine and 0.9% unidentified amine. Redistillation at 127 DEG-157 DEG C./0.2-0.3 mbar gave 259.3 g of a mixture of various triamino dicyclohexylmethane isomers containing 8.5% of diaminodicyclohexylmethane. The triamine was of the type containing two amino groups on one cyclohexane ring and one amino group on the other cyclohexane ring as substituents. (2b) 112.5 g of the hydrogenation product prepared according to (2a) and purified by distillation were dissolved in 1900 ml of dry chlorobenzene. Carbon dioxide was introduced into the resulting solution up to the saturation point. A colorless suspension formed and, after cooling to 0° C., was gassed with 600 g of phosgene while stirring. Next, add 3
Heat to 110℃ for 150℃ during this time.
g/h. After the solid was completely dissolved, the mixture was stirred under the same conditions for 4 hours. After dephosgenation for 1 hour and removal of solvent by distillation, the crude isocyanate was heated to 180-220°C/0.2
Distilled at −0.5 mbar. NCO content 39.1%
130 g of crude product was obtained. 174−180℃／0.1
Redistillation at -0.4 mbar gave 107 g of triisocyanato-dicyclohexylmethane corresponding to the formula () (R=H) in the form of an isomer mixture with an NCO content of 41% and a viscosity at 25 DEG C. of 112 mPa.s. Example 3 (3a) Nitration of methyldiphenylmethane according to European Patent Application No. 46917 and subsequent catalytic hydrogenation using Raney nickel yielded 2.6% diaminotoluene (isomer mixture), 6.2% diamino-methyldiphenylmethane. enylmethane (90% of diamines containing one amino substituent on each aromatic ring)
and 91.2% triamino-methyldiphenylmethane (a triamine with one amino group on the unsubstituted aromatic ring and two amino groups on the methyl-substituted aromatic ring) and 91.2% triamino-methyldiphenylmethane An aromatic polyamine mixture was obtained, consisting of an isomer mixture containing 350 g of this polyamine mixture were hydrogenated in a 0.7 liter stirred autoclave in the presence of 35 g of ruthenium (5%)/aluminium oxide supported catalyst and 35 g of ammonia at 200 DEG C./275 bar according to example (1a). After double distillation, the formula () (R=CH ₃ )
A hydrogenation product of 91% triaminomethyldicyclohexylmethane and 9% diaminomethyldicyclohexylmethane was isolated in a yield of 69.2 g (boiling point 132-148 DEG C./0.1 mbar). (3b) 63 g of the distilled hydrogenation product of example (3a) were dissolved in 400 ml of dry chlorobenzene and the resulting solution was saturated with carbon dioxide. The resulting white suspension of ammonium carbamate was dissolved in 150 g of phosgene in 400 ml of chlorobenzene.
(1.53 mol) was added dropwise at 0-10° C. with stirring. The suspension was then heated to reflux temperature, while phosgene was introduced until a clear solution formed after boiling for about 1 hour. After phosgenation for an additional 3 hours, excess phosgene was removed by injection of nitrogen. Removal of solvent by evaporation and 170-200℃/
After flash distillation at 0.1-0.3 mbar, 65 g of crude phosgenide were obtained. According to analysis by gas chromatography, 90% of phosgenide
% was triisocyanatomethyldicyclohexylmethane. Redistillation at 168-175°C/0.1 mbar yields formula (I) (R
= _CH3 ) corresponding to triisocyanatomethyldicyclohexylmethane 96.7% and diisocyanatomethyldicyclohexylmethane isomer 3.3
% polyisocyanate mixture.
The mixture has an NCO content of 38.65% and a viscosity of 196 mPa.s/
It was 25℃. Example 4 (4a) Example 2 in a 1.3 liter autoclave with stirrer
253 g (1.19 mol) of 2,4,4'-triaminodiphenylmethane obtained by recrystallization from 1,2-dichlorobenzene of the starting mixture described in
250 ml tert-butanol and the catalyst described in Example 1
50.6g was added. After repeated purging with nitrogen and hydrogen, 100 bar of hydrogen was introduced. The contents of the autoclave were heated to 180°C and then hydrogenated at 180°C/275 bar with vigorous stirring. Hydrogen absorption ceased after 105 minutes. The autoclave was cooled to 60°C, degassed and the catalyst was suctioned from the solution. After removal of the solvent by distillation, the crude product was subjected to flash distillation at 115-195°C/0.5 mm ball and 238.3 g
A distillate was obtained. 81.5% of the distillate is 2,4,
4′-triamino-dicyclohexylmethane,
16.1% was diaminodicyclohexylmethane and the remainder was unspecified polyamine. Purification of this product by distillation contained 2.3% (based on the entire mixture) of diaminodicyclohexylmethane and 175.4% of 2,4,4'-triaminodicyclohexylmethane with a boiling point of 147-153°C/0.2 mbar. g. (4b) 169 g of the hydrogenation product purified by distillation according to example (4a) were dissolved in 2.5 liters of chlorobenzene and the resulting solution was saturated with carbon dioxide. A suspension formed. The suspension thus formed was cooled to -20°C and the phosgene
Introduced 400g. After stirring for 15 minutes, turn off the phosgene flow.
15/h and the reaction mixture was heated to boiling temperature for 1 hour. The reaction mixture was then stirred again. The solids completely dissolved in 2.5 hours.
After a further 3 hours, the phosgene flow was stopped, nitrogen was introduced, excess phosgene was blown out and the solvent was drained at 15
Distilled at mbar. The crude product was then subjected to flash distillation under a vacuum of 1 mbar and analyzed by gas chromatography. 181 g of crude isocyanate were obtained. 86.8% (70.6% of theoretical value) is 2,4,4'-triisocyanato-
Dicyclohexylmethane, 9.0% was diisocyanatodicyclohexylmethane and 4.2% was unknown product. Redistillation at 180-185°C/0.2 mbar yields 95.5% 2,2,4'-triisocyanatodicyclohexylmethane and 4.5%
This yielded 162 g of isocyanate containing % diisocyanatodicyclohexylmethane isomer.
The isocyanate has an NCO content of 39.0% and
It had a viscosity at 25°C of 109 mPa.s. Although the present invention has been described in detail for the purpose of explanation,
The details are for that purpose only and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention except as may be limited by the claims. should be understood.

Claims (1)

[Claims] 1. A triisocyanate or an isomer mixture of triisocyanates corresponding to the formula [Formula] in which R represents hydrogen or a C ₁ -C ₄ alkyl group. 2. The triisocyanate or isomer mixture of triisocyanates according to claim 1, wherein R represents hydrogen or a methyl group. 3 In the method for producing a triisocyanate or an isomer mixture of triisocyanates corresponding to the formula [formula] (wherein R represents hydrogen or a C ₁ -C ₄ alkyl group), The above-mentioned production method is characterized in that an isomer mixture of triisocyanate or triamine corresponding to _C1 - _C4 alkyl group or a salt thereof is phosgenated.